This invention generally relates to a heat exchanger capable of withstanding high-pressure application. More specifically, this invention relates to a metal heat exchanger manifold to be used in automobiles where the manifold has an integral inlet/outlet port and a 360xc2x0 seal around the manifold.
Heat exchangers of the type, which are typically employed in air conditioning systems for automobiles, comprise separated manifolds with a large number of heat exchange tubes which carry coolant fluid between the manifolds. Traditional heat exchanges also comprise inlet and outlet tubes which are separately secured to the manifold.
In typical heat exchangers, each manifold comprises a tubular body that is internally divided by partitions or walls into a plurality of compartments to define a path for the coolant fluid through the heat exchange tubes. In addition to allow coolant to flow freely, it is also desirable for such manifolds to withstand high pressure. Such manifolds may be formed of two channel-like half shell, which are joined together along their longitudinal edges to form the manifold, with the partitions located transversely within the manifold. However, with such an assembly, difficulties arise in accurately locating the partitions or wall members within the manifold. If these are not accurately located, problems of leaking of the manifold can arise, as well as problems of partial obstructions of the heat exchange openings.
In order to accurately locate the partitions inside the manifold, it is known to seat these partitions in circumferential grooves machined on the internal surfaces of the tank and header part, which serve to position the partitions longitudinally therein. However, the problem with this arrangement is that in forming the grooves, the wall of the tank material is liable to deform, and in particular to elongate so that the intended groove locations cannot be accurately maintained.
Another method know in the art to provide a path for the coolant is to provide the tank part with seating slots extending entirely through the wall thickness into which the partitions are laterally fitted from outside of the manifold. However, in this method it is difficult to accurately locate the slots at the desired positions. Moreover, the slots provide additional possible leakage paths for coolant fluid. Prior art techniques have also disclosed a tubular manifold in which the partitions are held in position by deforming the tubular manifold wall on either side of the partitions by applying a circumferential beading. Other prior art technique have provided for insertion of baffles inside the manifold.
As is well known in the art, the coolant flows through the heat exchanger tubes that are typically inserted in the manifold. In order to insert heat exchange tubes into the manifold to facilitate the flow of coolants, slots are cut in the manifold. The heat exchanger tubes are then inserted to the slots. To seal the open ends of the manifold, end caps are provided that will prevent the coolant from leaking. However, these techniques have resultant in substantial leaking of the coolant through these slots.
A typical heat exchanger is assembled by inserting the heat exchanger tubes in the slots, the input and output tubes are then positioned and the end caps are positioned to cover the open end. The assembly is then brazed to bond the various components together. Therefore, the prior art techniques of assembling the heat exchanger involved accurate positioning of the various components to enable bonding of the components together. This technique was not only tedious but also involved manufacturing of separate components.
In view of the above, it is become desirable to provide a new design for the heat exchange manifold that allows for easy assembly of the heat exchanger. There is also a need to provide for a heat exchanger that can be brazed with ease and can with stand high pressure application.
Accordingly, this invention provides for a two-piece heat exchanger manifold that overcomes the problems and disadvantages of the conventional heat exchangers known in the art. The invention provides for a heat exchanger comprising a two-piece manifold and heat exchanger tubes coupled to the manifold.
In accordance with the teaching of the present invention, the manifold comprises of two parts: the header and the tank. In one aspect of the invention the header, consists of several half cylinders formations that are stamped on a sheet of metal. Another aspect of the present invention provides for communication ports that are stamped on the header of the manifold. The communication ports in the present invention are in the form of channels that allow the coolant to flow and mix through out the manifold.
Yet another aspect of the present invention is the presence of another set of half cylinder formation disposed perpendicular to and intersecting the first set of half cylinders. The ferrule openings are cut in the base of the second set of half cylinder. The ferrule openings are cut such that they coincide with the communication channels in the header of the manifold. The ferrule opening allows for a heat exchanger tube to slide inside the manifold and also help in the ease of brazing.
The invention also provides for a tank that consists of several other half cylinder formations which when combined with the header half cylinder, form several complete cylinders. Yet another feature of the present invention is the presence of 360xc2x0 seal around the mating edge of the manifold for better sealing between the header and the tank. This eliminates the need for the end caps or other sealing devices to mate the header and tank.
Yet another aspect of the present invention is the manifold consists of an integral inlet/outlet port that are stamped on the header and the tank. The integral input/output port allows for an easy assembly of the heat exchanger manifold in accordance with the teachings of the present invention.